| 摘要 |
<p>In a control system (28) for a hydraulically operated draw works or the like having a hydraulically disengaged brake (14), a transmission (10, 12) and a brake control valve (114, 122), an accumulator (174) is provided having a check valve (196) connected between the brake control valve outlet (152) and the brake (14) to modulate application of the brake (14) when it is applied after the brake (14) has been fully released and to provide unmodulation application of the brake (14) when it is applied after the brake (14) has been only partially released, thereby to minimize shock in the draw works components when a load is lowered rapidly and the brake is then applied and yet provide rapid actuation of the brake when the load is being lowered slowly.</p> |
